1. Field of the Invention
The invention relates to a new steel composition for special uses, in particular displaying high performance in the presence of corrosion due to oxidising environments such as, for example, fumes or water vapour, under elevated pressure and/or temperature.
2. Description of Related Art
Atmospheres of elevated pressure and temperature in the presence of water vapour exist in particular in the industrial production of electricity. The generation, conditioning (in particular superheated and re-superheated) and transportation of the water vapour take place using steel elements, in particular seamless tubes. Despite a long history of solutions envisaged or implemented, which history will be returned to hereinafter, serious problems remain in terms of resistance in the atmosphere in question, and also over time.
These problems are particularly difficult to solve, in particular due to the significant variability of the properties of the steels as a function of their constituents, and to the awkwardness of the hot corrosion tests over a long period.
The term “corrosion” or “hot corrosion” will be used hereinafter to designate the phenomena of the loss of metal by hot oxidation.
The present invention seeks to improve the situation.